What is Flat Grain?

Flat grain refers to wood that has been cut perpendicular to the tree’s growth lines. Flat grain wood is not as stable or sturdy as vertical grain lumber.

Flat grain results when trees are cut in parallel portions by sawing a perpendicular cut to its growth lines. This technique is often used to create veneers. Flat grain lumber has two sides: the bark side and the pith side. The bark side is the portion of the lumber that was closest to the exterior layer of the tree. The pith side was closer to the tree’s center. Flat grain lumber is prone to swelling and changing with age. Professionals recommend exposing the bark side of flat grain lumber because it will not experience as much grain separation as the pith side. Changes in the lumber can be minimized by using a saw-texture on the wood’s surface. Fine grain lumber is frequently available and is often less expensive than straight grain lumber. However, its vulnerability to weathering and damage makes it a less suitable choice for many types of projects.